Construction of metal girders



Jan.5,1937. D 5mm, l 2,066,315@I CONSTRUCTION OF METAL GIRDERS FiledAug. s, l1953 2 'shees-sheet 1 lINVENTOR Dxm'rm BmxxN By '/OA Jan. 5,1937. D. BIRKIN v2,066,388 n CONSTRUCTION OF METAL GIRDERS Filed Aug.25,v 1953 2 Sheets-Sheet 2 Patented Jan. 5.19.37 l

UNITED s'riiiiis- PATENT OFFICE CONSTRUCTION METAL GIRDERS DimitriBirkin. Berlin, Germany, assignor to iirm Edward G. Budd ManufacturingCompany,

Philadelphia, Pa. y

Application August ze, 1933, serial No. 686,364

InGermany September 17, 1932 The invention relates to metal girders, andparticularly to triangular or quadrangular girders, which are formed bybeams and stays connected to one another.

connections between the beams and the stays have been eithercomplicated, expensive and heavy to construct because of the employmentof connecting plates or the like.. or the connec- '15 simple means of.extending the stays towards one another' at an angle and engaging themat ag suitable place in the beam is adjacent corresponding opposingwallsections-of the beam with their walls running in the longitudinaldirection of the beam lying opposite one'another and is connected withthem preferably by spot welding. Preferably sheet metal of rustlesssteel alloy, such as chrome-nickel steel, is employed in the individualstays and the connection of the elements preferably effected by 'spotwelding. As the sheet metal sections per se and the sheet metal sectionsemployed, possess very great solidity,v andI bending strength inproportion to their weight, since in the application of such rustless 3metalno allowance needbe made' for rusting-oi! in the calculation ofsolidity, and also, since no painting is necessary, the girder of theinvention is of exceptionally light weight compared to known girders ofsimilar strength. Girders constructed in accordance with the inventionarev particularly desirable for the construction of flying-machines, forvehiclel construction, for an.` tennae and for other devices. Theimportance of areduction in weight in a ying machineis known. Also, forantennae, a s'mall weight is of much importance, as in small antennaefor military purposes, which are transportable. For larger antennae, thesize of the insulators carrying them and the remaining foundations, the

construction of which is usually very diiilcult, de-

pend very largely on the weight of the antennae.

.Further characteristics -of `the invention will appear from thefollowing description of the examples illustrated in the drawings.

56 Fig. 1 illustrates in schematic perspective view a triangular girder;

Figs. 2-'7 illustrate sections which may suitably be employed as stays;

s. Fig. 8 ,illustrates a cross section through a triangular girder;

f1o claims. (cuss-31)'- In such structuresheretofore employed, thevsection. Flanges I6,

Fig. 9 illustrates in plan a junctionpoint, lookingv in the direction ofthe arrows vIi--IL Fig. 8;

Fig. 10 illustrates one of the thiee junction points shown in Fig. 9 toalarger scale with a 'somewhat different arrangement of stays; 5

Fig. 11 illustrates a unction point corresponding' to Fig. 10 with staysmeeting at an angle of Figs. 12-16 illustrate' different forms ofconstruction of the connection between stays and 10 beams correspondingto Fig. v10.

'I'he girder illustrated in- Fig. 1 comprises longitudinal beams I, 2,3, sets of stays 4, 5, 6, each forming a triangle, and connecting thebeams to one another, and a set of diagonal stays 1, 8, 9 l5 disposedbetween each pair of sets of th'e stays 4, 5 and 6. i The stays, asindicated in Figs. 2-7. are formed with opposite walls -a and bextending parallel to each other. 20

I n the examples illustrated in Figs. 8-11 each unit yhas a channel,which comprises' a base part I0 and two side-walls II and I2.

The flanges I3, I3,V serving mainly forstrengthening, are bent up fromthe edges of' the base 25 part III. vThe connection of the side wallmembers III and I2 to the base wall I0 is effected by means ,of angesI4, I4, bent up from, the side wall portions. Thel side wall parts I2consist of two parts IIa, IIb or I 2a, I 2b extending towards 30 eachother at an angle forming a V-shaped cross- I6, serving for furtherstrengthening, may be bent up from the free edges A of the side wallportions Il, I2.

The ends of the stays 4 and 5 are welded to 5 I the parts Ill-I2. Thestay '4, of which the cross section is formed according to Fig. 4, isdisposed with its wall a, formed by iiangeaagainst the wall section IIaof the beam thereof and with.

fits base wall b against thev wall section'l I2b, to 40 which it isconnected preferably by welding.' In similar manner, the wall a of thestay 5 is con,- nected to the all section I2a of the beam and,

the Vwall b to t e wallsection IIb thereof.

As shown in Figs. 8 and 9, the stays 4, 5 and 6, of 45 each set thereof,formingvwith each other a triangular brace, do notv extend absolutelyperpendicu lar to the longitudinal direction of the beam, but each stayis disposed at a slight angle tothe plane of its set, so that eachadjacent pair of stayends 50 engaging a beam lie in adjacentsideyby-side, or longitudinal overlapping, relation to one another forlongitudinal side-by-side positioning, each beyond the adjacent Aend ofthe adjacent stay.

In theexamples illustrated in Figs. 8-and 9, 55

the stays 4, 5 are connected to the wall sections `Ila and l2a of thebeam and the walls b to the .wall sections I2b and-I Ib thereof.Although detracting somewhat from the appearance of the construction tohave the stays opening outwardly, this construction has an advantageover the construction illustrated in Figs. 8 and 9, in that the staysmay be placedin close relation to each other, since the side-flanges ado not cross.

The example illustrated in Fig. ll-differs essentially from the exampleillustrated in Fig. l0 only in that the stays approach each other at anangle of 90 instead of 60.

In the examples illustratedthe front faces of the stays may run parallelto the base part i0 of the beam, as in Fig. 11, or be sloped sharplythereto, as illustrated in Figs. B and 10. The sharp sloping avoidsacutting operation of the stay flanges which extend toward each other inthe arrangement illustrated in Figs. 10 and 11.-

responding manner, as indicated in Fig. 11, the

portions of the stays lying outside the beam may be closed by strips ofmetal sheet ita connected to the flanges a of the stays,-so that thestays become of closed box-section.

In the form of the cross section yof the stay illustrated in Flgs.,8 and9, vparts I0, Il and l2 of the beam may be united before theirassemblage with the stays; the structure, astl'iusl formed, admittingthe ends of the stays. In the form of the cross section of the staysillustrated Figs. 10 and 11, the stays are ilrst connected to the .partsI0 and H of the beam, after which, the union of the base wall l0 to theflanges I4 of the parts I0 and II is effected. Otherwise, the places ofconnection of the walls b of the stays 4 and 5 to the wall-sections libi2b of the beam would be inaccessible.

The example illustrated in Fig. 12 differs from the examples previouslyillustrated only by the construction of the base plate-I0 of the beam,to flt the flanges i4 of the side wall portions Il and I2 of the beam,which are directed toward each other. Instead of the Z-shapedcross-section of the stays 4 and 5 of this example, other cross-sectionsmay be employed, without alteration of the oros section of the beam.

'Ihe example illustrated in Fig. 13 differs vfrom the previouslyillustrated examples by consist-J ing of two opposite parts I9 and .20.The part i9, forming a simple angle iron', is .connected to the .outerside walls b of the stays 4 and 5. The beam section 20 formingv asimilar simple angle l iron, is connected to the inner side flange sectothe rail 2i.

tions a of the stays. The opening of the angle iron 20 may be formed asa closed box girder by a rail 2i, which is placed in position after theconnection'of the rail 20 to the stay. For effecting the connection,flanges 22 and 23 rare bent from the rail 20 and preferably spot weldedAlso the rail I9 may be completed as a closed box girder aside theplaces of entry of the stays by flanges bent inwardly therefrom similarto the `flange 22. Y

In the example illustrated in Fig. 14, the beam comprises a doublechannel-shaped portion 24, in which one stay 4 is connected to the vsidewalls 25a, 25h, of the one channel and the second stay 5 is connected tothe side walls 26a and 26h. For strength, lateral flanges 21 may be bentup from the part 24, and for further strength, and also for improvedappearance, a channel-shaped covering-rail .28 may be` connected to therail 24 by means of flanges 29 adjacent to the flanges- 21.

In place of the stayisectlons, illustrated in'v Figs. 13 and 14 otherstay sections may be em-f s ployed, without alteration of the shape ofthe'.

beam.

Besides the examples previously describedla large number of other formsare possible. This is especially true of the cross sections of the staysand beams. In connection with the forms, illustrated in Figs. 8-11, thejunction place'between the part forming the base wall and the Partsvforming' the side walls Il and l2,-may be disposed at another place andmay be formed in another manner, as indicated in Figs. 15 and 16. In theconstruction of the sections and the under portions thereof, care mustbe taken that the places of connection areaccessible for the insertionof welding electrodes, or rivets and riveting tools. In the applicationof rustlessv steel alloys the welding is preferably effected duringexceptionally short time intervals, such as between 1/25th and 1/500thof a second, and preferably about one 200th of a second, with the ap-'35 plication of a correspondingly powerful current. Thus the propertiesof the material of the stays and beams at the welds, and at the partslying about the welds, especially the strength, are notdisadvantageously altered, as in welding processes of longer timeperiods heretofore usual.

What is claimed is:

1. A girder comprising sheet-metal beams of hollow divergent sectionlaterally spaced about a common axis, an adjacent pair thereof having rinside pairs of spaced inner surfaces diverging as pairs crosssectionally of the girder, and transverse sheet-metal stays havingtransverse stay surfaces of adjacent. ends of a lpair of stays extendingalong the adjacent beam opposite one another and secured in flat-sideengagement each to yan inside pair of said diverging beam surfaces ofthe adjacent beam inside the hollow section thereof.

2. A girder comprising sheet-metal beams of e hollow section laterallyspaced about a common axis and each including separate base and sidewall elements secured to each other to form a channel, the side wallelements of each beam being of substantially V-section one arm of whichhas an angularlybent flange secured in :dat-'side relation to the base,and transverse sheet-metal stays having surfaces of adjacent ends ofeach pair of stays extending along the adjacent beam.

and side-wall elements secured to each other to form a channel, the sidewall elements of said beam having inner surfaces diverging crosssectionally of the girder, one of said side wall ele-l ments having amarginal flange bent outwardly therefrom and connected to the baseelement, and transverse sheet-metal stays having surfaces of adjacentends of the pair of stays extending along said one beam opposite oneanother and secured' to said diverging side wall beam surfaces insidethe hollow beam section.

5. A girder comprising sheet-metal beams of hollow section laterallyspaced about a common axis, one of said beams including separate baseand side-wall elements secured to each other toform a channel, the sidelWall elements of said beam having inner surfaces diverging crosssectionally of the girder, and transverse sheet-metal -stays havingsurfaces of adjacent ends of each pair of stays extending along theadjacent beam opposite one another and secured to said diverging sidewall surfaces of the adjacent beam inside the hollow section thereof,said base element havingedge margins bent in the direction of theadjacent stays.l

6. A girder comprising sheet-metal beams laterally spaced about a commonaxis, and transverse sheet-metal stays of channel section includingbottom walls and side walls having freeedge flanges. the said staysextending transversely of the girder and the surfaces of said bottomwalls and flanges at adjacent ends of a pair of stays extending alonginside the adjacent l 3 beam opposite one another and secured ilatwisethereto.

7. A girder comprising sheet-metal beams iat erally spaced about acommon axis, transverse sheet-metal stays of channel sectionincludingbottom`walls and side w'alls having free-edge flanges, the saidstays extending transversely of thegirder and the surfaces vof saidbottom walls and flanges at adjacent ends of a pair of stays extendingalong the adjacent beam longitudiv nally opposite one another andsecured iatwise thereto, and elements secured along the stay flangesrendering the stays of closed box sections.

8. ln a girder, a chord member having side walls converging toward eachother and ea'ch terminating short of the projected plane of the other,and stays of angle cross section having their ends projected between theface of the one side wall of the chord and the edge of the other sidewall and secured fiatwise by one branch of the angle cross section tothe inner face of the one side wall.

9. A girder according to claim-8 in which the side walls of the chordhave their free edges divergently extended ,each parallel to the innerface of the other side wall, and the angle cross section members eachsecured by another branch of their angle cross section to the extended4free edge of the opposite side wall from that to whose inner face it issecured. Y

10. A girder comprising a sheet metal chord having opposed pairs of sidewall faces. each. face comprising portions extending at an angle to eachother, and an angular section' stay extending between' the pairs of sidew'all faces and having one of its arms secured fiatwise to one angularportion of one of said faces and another of its arms similarly securedto the other angular portion of the opposite sidewall face.

DMTRI BIRKIN.

